Process of dislodging slime cakes.



e, W. SHEPHERD. v PROCESS OF DISLODGING SLIME CAKES.

APPLICATION FILED MAY I 1913.

Patent-ed May 12, 1914.

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GEORGE W. SHEPHERD, OF NEV] YORK, N. Y., ASSIGNOP. TO TEHE B'UTTERs P ATENT VACUUIvI FILTER COMPANY, INC.. A CGRPORATION OF NEVADA, v

res-cones or msLone-ine SLIME cases.

insane.

specification of Letters JPatent. Pateutgdfifay Application filed May 1. 1913. Serial No. 764,842.

To I? ((720222 '56 may concern Be it known that I. Gr use Y. SHEPHERD,

My invention consists in applying water under pressure externally of the filter leaf in such a way that the time for the cake dislodgnient is materially shortened and the surface of the leaf is thoroughly cleansed.

Specifically my invention consists in applying water under pressure near the top of the leaf and un lcrneath the surface of the cake for a substantial distance between the cake and the filter medium.

By my invention the cake may be coni pletely dislodged without any internal pressure whatever, thus saving the filter medium the wear and tear incident to internal pressure but it may be used with internal pressure also, if desired.

My process of cake dislodgement has a great atlt'antage over other processes of external'dislodgment, in that they apply the spray or sheet of water on to the outside of the cake. while by my process the water is applied beneath the surface of the cake or inside the cake. In former processes the tendency of the water was to make the cake adhere more closely to the filter leaf by reason of the external pressure and wetting of the cake caused by the spray. In previous processes the cake would hang on to the r! filter medium until washed away or carried off piecemeal or in a solution, so to speak. ly my method I force the cake away from the filter medium in bull: by pressure and do not depend upon piece-meal washing away of the cake. It is sometimes found that when pressure is created between the cake and the filter medium according to my process they are separated a distance below the opening in the dislodging pipes before the cake is separated at its top thus confining the pressure for a short time between the cahe and the medium; This'is for :1? short tnne only. however. so 'tlri'twhen th' top is separated the cake come clear ofnie dium thereby cleaning the tlr in a very short time. i '60 My invention has many advantages. chief of which is the saving in time and in amount of water used. It is to remembered that water is valuable in a largeiplant and con: siderable saving thereof is greatly to" be appreciated. Other advantagesof my'invcntion will be apparentafter re adingthe' following detailed description taken'iiicom nection with the accompanyingdrawings; in

whic.h- 1t igure 1 1s side elevation of a fil't'er leaf" which may be used in my fproce ig.

' for stipply ed F gis a bottom view of pipinp used ing water to dislodge tho-cal. is an enlarged section onilin 1 with a cake thereon shown in dotted line In Fig. l, t represents the frame; whicli" may be of any construction..bnt(it; prefe v ably consists of tubing. thebot'toni.niember 5 of which is perforated orslotted, tliepe forations or slot opening intot-he intei l of the leaf. his member is connected this instance through the..rightrha'nd"endj frame-member with a 1C;. }1Z11 fi is ed; shown. througl'i any suitable connec "i f 7-'T are fil er media. gone on each H the frame. These are hcld'apart during the. filtering process by any suitable spacing f means such as wooden stic-ksS. (The filter me-f dia are stitched together-was show 'ngat, dotted lines 9, for the purpose ofholding .tliefspacingj sticks in place. Any number o be placed between successive I tions. This stitching isuse ballooning if internal pressu the leaf. The upper parto V 7 is securely clamped between 1 16 by means of bolts 15. v i 1 1 1. 2 represent small pipes running along the upper portion of the leaf. Each of these pipes has openings or a slot 10 along the length thereof extending substantially the whole length of the leaf. These slots or connected to the supply pipe 12. It is desirable that the openings in the pipes 1. 2 be so arranged that they will lie beneath the surface of the cake which is formed (hiring the filtering operation so that when water is adi'nitted to the pipes it will be initially applied beneath the surface of the cakes and between the cakes and the filter media. It may be found desirable in some cases to protectthese slots or openii'igs so as to prevent the deposit. by sedimentation or otherwise. of particles therein. that end a suitable valve, such as a checkvalve 11, is placed in the p'ipelQ through which water under pressure is admitted to the dislodging pipes l and This valve is arranged to open toward the leaf and to close in the reverse direction so that there will be no movement of liquid into the pipe 12. The pipe 12 is connected with anysuitable water supply under pressure.

hile the dislodging pipes 1, 2 are shown as being on a level with the. lower side of the top frame pipe it is to be understood that my invention is not limited to this arrange ment, as they may be either above or below this point. These pipes may be of any desirable shape in cross-section. v

It is understood, of course that my process may be used to dislodge cakes under many conditions. In fact, it can be used as a step in any of the processes of filtering; now in use. Specifically it may be used. to dislodge a cake while the leaf is submerged or while the leaf is suspended in air. It is also applicable whetherv or not internal water exists in the leaf, also with or without internal pressure, as for instance, after decanting the water bath. It may also be used with or without drying the cake by continued vacuum after the cake is removed from liquid.

While I have described my invention with the use of water, I have done so for convenience only, as air or other fluid may beiused with satisfactory results. and all are within my invention. ater is generally used for this purpose, however, and is preferred.

My invention is not limited to any particular kind of pipe or passage for dislodging fluid as there may be many ways of accomplishing this. In its broadest aspects my invention is independent of the means for admitting fluid under pressure beneath the surface of the cake formation. I filed, on September 3, 1913, a d'visional .838. in which I claimed-a leaf process claimed Having described my invention what I' claim as new and desire to secure by Letters Patent i.

1. The procof tiii lod 'ing cakes from filter leaves which eonv s in admittin; a lvlfcsi are medium into the cake near the surface of the filter medium.

QfThe process of dislodgine cakes from filter leaves which consists in admitting:

fluid under pressure into the cake nearthe from tlui d tancc be a o'ilsaid 3 in apply ing water under pressure for a substantial' distance beneath the surface of the cake and outside of the leaf.

The process of dlslodginn slime cakes from filter leaves. which. consists in apply ing waterundcr pressure at the top portion of the cake and beneath the surface thereof.

6. The process of dislodging' slime cakes from filter leaves. which consi'sw in applying a sheet of water between thematic and the tiller medium.

The ,process of dislodgi'nfl a slin c cake from a filter leaf, which consi ts in applying a stream of water the wh the leaf between the cake and the filter niedium. i l

8. The process of cleanin of slime cakes, which cons sts in applying a substantially uninterrupted stream of water at the upper interiorportion of the cakes.

9. The process of cleaning a filter st of slimeicakes, whichc'onsists in ap' l' sheet of water under pressure sub along the upper line of cake formation and beneath the surface of said ealrc.

Int-estimony whereof; I have signed my a filter surface name to this specification, in the. presence of two subscribing witnesses. v

GEORGE W. SH EPHlfil-ll).

'VVitnesses: v u

I Enwm Scene. 1 Nnw'rox A. BCRGESS. 

